Digital imaging has vastly increased consumers ability to produce viewable images from both professional and amateur image records on the same output system. The term “viewable image” is used herein to refer to images that can be visually perceived, such as light images produced by a display and hard copy images produced by a printer or press. The term “image record” is used herein to refer to a digital still image, video sequence, or multimedia record. Output systems sometimes provide minimal automated digital processing of the output image records. In other cases, “one-size-fits-all” processing is provided. These approaches work best with a narrow range of input and are not helpful for image records that do not fit that narrow range. Manual (user directed) digital processing is commonly available and is not particularly burdensome in some situations, such as editing and printing individual still images. On the other hand, manual digital processing can be very burdensome for editing video sequences. Manual processing is also not suitable for use during casual viewing. Output systems that display images, also referred to herein as “display systems”, are, thus, particularly suitable for automated digital processing.
Examples of playback systems include home entertainment systems, televisions, and portable devices providing similar functions. Many playback systems now include subsystems that apply sophisticated image processing algorithms. Such algorithms can alter one or more of: noise, contrast, color balance, brightness, and other image quality parameters. Such algorithms can greatly improve consumer image records, particularly image records that have never been edited or have been captured using a camera lacking in sophisticated image processing. Such algorithms can also modify the “look” of professional image records. The term “look” is used herein in the same sense as in U.S. Pat. No. 6,868,190 to Morton and U.S. Pat. No. 6,972,828 to Bogdanowicz et al., which are hereby incorporated herein by reference. These patents disclose procedures for maintaining a desired “look” in a motion picture. “Look” includes such features of an image record as: sharpness, grain, tone scale, color saturation, image stabilization, and noise. These references teach modification of input image records of a known look to create an output image record of a different look. Unfortunately, in many cases, the look of the input record is not known or characterized.
Modifying the look of professionally prepared image records raises issues of whether artistic values have been compromised. It is a shortcoming of many playback systems that image records are all automatically modified. This is problematic if the look is changed.
It is known to modify the encoding/compression of TV images depending on the source, as explained in “Source-adaptive encoding options for HDTV and NTSC” by Parulski, et al, SMPTE Journal, October 1992, pages 674-683.
U.S. Pat. No. 6,671,405 to Savakis et al. teaches use of a Bayesian network or group of networks to provide an automatic ranking of consumer images in terms of their logical order based on an automatic assessment of emphasis and appeal, but the ranking of images is determined for automatic album page assembly. U.S. Pat. No. 6,671,405 describes a number of features that have been selected based on a ground truth study of the preference of human observers. These features include people related features: the presence or absence of people, the amount of skin or face area and the extent of close-up based on face size; objective features: the colorfulness and sharpness of the image; and subject related features: the size of main subject and the goodness of composition based on main subject mapping. The outputs of the feature extraction stage thus represent statistical evidence of the presence (or absence) of certain features; the outputs are then integrated by the classification stage to compute a value representative of the likelihood that the image is of the type the network is designed to detect.
It would thus be desirable to provide methods and systems that overcome these shortcomings.